"While I agree that glaciers are melting because of global warming, if this is because of man, then what was the reason for the melting of the glaciers in the Gondwana period long before man arrived on the planet?" asked Dhruv Sen Singh, Centre of Advanced Study in Geology, University of Lucknow.
"Climate change is a natural phenomenon while pollution is caused by man. We are definitely accelerating the process of climate change, but we cannot predict the rate or extent of climate change that can be attributed to man," Singh said.
According to him, fears of climate change amount to propaganda and "unnecessarily cause panic".
"The Cretaceous period 65 million years ago was the hottest in the history of the earth. Man was not around at the time," he added.
Singh said that if climate change was the cause of glaciers retreating, they should all be retreating at the same rate. "But in reality they are retreating at different rates, and some were advancing," said Singh. "Despite the melting of glaciers, only at some places the sea level is rising, whereas at others it is constant, possibly due to the sinking of land," he added.
As for extreme climatic events such as the Uttarakhand cloudburst, he said such cloudbursts were not new to the Himalayas. "These are cyclical events but not catastrophes. The devastation in Uttarakhand was caused by people living in hazard-prone areas, a function of India's high population density," he added.
Rajesh Agnihotri senior scientist at the Radio and Atmospheric Science Division, National Physics Laboratory, who mapped changing trends in India's monsoons, said there was nothing to suggest that this was because of man-made climate change.
Hypothetically, even if man stopped industrial activity, stopped using cars and stopped using air-conditioners, monsoon patterns would still change," said Agnihotri.
"Natural forces like solar intensity appear to be dominating monsoons to a greater extent than man-made climate change," he added.